A fossil dealer's guilty plea has set the stage for what is most likely the largest dinosaur fossil repatriation in history, according to an attorney representing the president of Mongolia — the country that will receive most of the fossils that federal officials are seizing from fossil dealer and preparer Eric Prokopi.

On Thursday, Prokopi pleaded guilty to criminal charges related to smuggling fossils and agreed to forfeit a small menagerie of dinosaurs to federal officials. All but one of the dinosaurs in question came from Mongolia, where law makes fossils state property, and among them is a high-profile skeleton that received a $1.05 million bid at auction.

"We have looked into this, and we can't find any instance anywhere when one country has returned to another a lot of dinosaurs this large and this significant that have been looted or smuggled," said Robert Painter, attorney for Mongolian President Elbegdorj Tsakhia.

The outcome has set precedent in other ways, according to observers and others who are involved in the case. In particular, some believe it will send a message to those involved in the black market for fossils, particularly those taken from Mongolia, which have been widely available for sale.

A long list of dinosaurs
In May, Prokopi put his 8-foot-tall and 24-foot-long (2.4 meters by 7.3 meters) Tarbosaurus bataar specimen up for auction. President Elbegdorj and several paleontologists objected, saying the dinosaur was almost certainly pilfered from Mongolia. The Manhattan U.S. attorney's office became involved and sought legal possession of the dinosaur with the intent of returning it to Mongolia. Later, Prokopi was arrested on federal smuggling charges. [See Images of the Smuggled Tarbosaurus Skeleton]

In a plea deal, Prokopi pleaded guilty to three felony counts and agreed to give up his claim on this dinosaur, plus fossils from two other Tarbosaurus bataars, which are Asian relatives of the better-known Tyrannosaurus rex; one Saurolophus or duck-billed dinosaur; and two birdlike Oviraptors. In September, federal officials seized another Saurolophus that Prokopi had sold to California-based gallery and auction house I.M. Chait. A small four-winged Microraptor from China was taken by federal officials before this case began. One of the Tarbosaurus fossils is believed to be in Great Britain.

"We are pleased that we can now begin the process of returning these prehistoric fossils to their countries of origin," Preet Bharara, the U.S. attorney for the Southern District of New York, said in a statement.

Prokopi's prospects
After pleading guilty to charges of smuggling, making false statements on customs forms and dealing in fossils he knew to be illegal, Prokopi faces a maximum of 17 years in prison and a substantial fine. However, his defense attorney Georges Lederman said he believes it is highly unlikely Prokopi will receive anything close to the maximum sentence.

"We are confident that the sentence imposed will be a fair and reasonable one and will take into account all the proactive measures my client has made," Lederman said, noting that Prokopi has cooperated with investigators and, as part of his plea deal, will continue to do so.

The outcome of the case disappointed David Herskowitz, an independent natural history consultant. While employed by the auction house Heritage Auctions, Herskowitz arranged for the sale of Prokopi's Tarbosaurus.

"I know Eric, and I know he is not a criminal," Herskowitz said. "I don't believe he knowingly broke any laws, and I believe the only reason why he had to cop a plea was financial and the pressures [of being involved in a court case]."

Prokopi spent a year preparing the Tarbosaurus fossils, which were once rough fossils that made up about 75 percent of a skeleton, to create a complete, mounted specimen with the intent of selling it at auction, Herskowitz said. But the $1 million sale was never completed.

Since releasing a statement in June, in which he described himself as "just a guy in Gainesville, Florida, trying to support my family, not some international bone smuggler," Prokopi has been silent.

At roughly the same time federal officials seized the Tarbosaurus bataar, fossils of probable Mongolian origin were easily found in auction catalogs and on eBay. Herskowitz noted that he has seen Mongolian fossils for sale during the 20 years he has been working in the field.

"Mongolia never stepped forward to do anything about the buying and selling of Mongolian fossils, and that was the reason why everyone felt it was legal and OK," Herskowitz said.

A legal question
With the deal still fresh, not everyone agrees about its legal implications. An important issue in the case was the relationship between Mongolian law — which Prokopi’s civil attorneys said did not clearly make fossils state property — and U.S. law. This is important because prosecutors were basing the claim that the fossils were stolen on Mongolian law; however, Prokopi was being prosecuted under U.S. law.

From Herskowitz’s perspective, the plea deal doesn’t resolve this issue, but the ambiguity will likely change the market.

"I would believe that no one should be selling Mongolian fossils until this whole thing is resolved," he said.

Ricardo St. Hilaire, an attorney who practices cultural law, disagreed, saying that the deal created a foundation for using Mongolian law on cultural property to invoke U.S. law on stolen property.

"This conviction should signal to those of us in the legal community and to anybody in the collecting community that Mongolian law has served as the basis to trigger the National Stolen Property Act," St. Hilaire said. Prokopi pleaded guilty to one count of violating this law. [Faux Real: A Gallery of Art Forgeries]

The case and its outcome signal the willingness of the Manhattan U.S. attorney's office to pursue cultural property cases, said St. Hilaire, who has been following the case and writing about it on his blog.

Robert Painter, the attorney for the Mongolian president, put the significance in more blunt terms: "Smugglers like Eric Prokopi used to think they could do this with impunity. Now they realize this is very serious."

The Mongolian reaction
Mongolian officials have announced plans to establish a temporary facility in the central square of the capital, Ulaanbataar, to display the dinosaurs once they return, Painter said.

"President Elbegdorj and Mongolians are so grateful for what the U.S. government has done, there is just a tremendous amount of excitement," he said.

The dinosaur's saga from auction block to courtroom has captured Mongolians' attention: A Mongolian media company, Shuud.mn, named the dinosaur's story the top event of the year, said Bolorsetseg Minjin, a Mongolian paleontologist who has advocated for the return the dinosaur.

"It is not only on the news, just talking to the people in Mongolia, they really want to know what is going on with the whole case," Minjin said.

Mongolian officials are investigating the illicit trade within their own borders as well, Painter said.